Write a Python function to find the longest palindrome in a list of binary numbers.
Posted by BobHarris
Last Updated: August 09, 2024
## Finding the Longest Palindrome in a List of Binary Numbers Palindromes are sequences that read the same backward as forward. In binary, this applies to strings composed of '0's and '1's. To identify the longest palindromic binary number in a list, a Python function can be implemented to achieve this efficiently.
Functions and Implementation
Here is a Python function that iterates over a list of binary strings, checks for palindromes, and keeps track of the longest one found.
def is_palindrome(binary_string):
    """Check if the binary string is a palindrome."""
    return binary_string == binary_string[::-1]

def longest_palindrome(binary_list):
    """Find the longest palindrome in a list of binary strings."""
    longest = ""
    for binary in binary_list:
        if is_palindrome(binary):
            if len(binary) > len(longest):
                longest = binary
    return longest

# Example usage
binary_numbers = ['110', '101', '1001', '111', '10001', '11111', '100001']
longest_palindromic_binary = longest_palindrome(binary_numbers)
print(f"The longest palindrome is: {longest_palindromic_binary}")
Explanation of the Code
1. is_palindrome Function: This helper function takes a binary string as input and checks if it reads the same backward. It uses slicing (binary_string[::-1]) to reverse the string and compares it to the original. 2. longest_palindrome Function: - Initializes an empty string longest to keep track of the longest palindrome found. - Iterates through each binary number in the input list. - For each binary string, it checks if it is a palindrome. If it is and its length is greater than the current longest, it updates longest. 3. Example Usage: The list of binary numbers is defined, the function is called, and the result is printed.
Complexity Analysis
- Time Complexity: The function runs in O(n * k), where n is the number of binary strings in the list, and k is the average length of those strings. The palindrome check operates in O(k). - Space Complexity: The space usage is O(1) beyond the input storage since only a few additional variables are maintained.
Conclusion
This approach efficiently identifies the longest palindrome from a list of binary numbers, leveraging string operations in Python. This function can be readily adapted for various applications where detecting patterns in binary sequences is necessary.